"If the Cap Fits..." is the sixth episode of the fifth series of the British television sitcom Dad's Army. It was originally transmitted on 10 November 1972. Synopsis Mainwairing is giving a slide show, but Frazer comments he is wasting everyone's time on a fine summer evening with another irrelevant lecture. Mainwairing decides to let Frazer take over for a few days to assuage his grumbling. Plot The episode opens with the Walmington-on-Sea Home Guard unit in the church hall, waiting for Mainwaring to give a presentation. The platoon is disgruntled at being shut in on a fine summer evening and, led by Frazer, they begin a chorus of "Why are we waiting", which sounds like O Come All Ye Faithful. Mainwaring enters and tells them to be quiet. He begins to give them a farcical slideshow entitled "Know your enemy", which contains exaggerated drawings of German infantrymen, panzer crew and parachutists. The show is narrated languidly by Wilson, who insists on wearing a monocle. Mainwaring interjects with stereotypical comments such as: "Note the eyes – close together, mean, shifty – that's typically Nazi" "Look at the thick red bull neck, watch out for that" "He has no lobes on his ears, a well known criminal trait" Jones is attempting to operate the projector, much hampered by the Verger, who is there to prevent any "damage to the Vicar's apparatus". Godfrey is asleep, whilst Walker and Pike interject with silly questions. Hodges arrives, and accuses them of looking at dirty pictures, and Jones finally messes up, showing a picture of a topless Zulu woman from the Vicar's slide collection, "Light into Darkest Africa", much to Hodges' delight and Mainwaring's discomfort. Afterwards in the office, Mainwaring threatens to stop Wilson wearing the monocle, but Wilson responds by threatening to tell everyone that Mainwaring wears arch supports for his feet. Frazer enters, and not only tells Mainwaring the lecture is a waste of time, but consults notes he has made and reminds Mainwaring of other similar irrelevant lectures, such as "Why the Germans don't play cricket" and "How to send Hitler a poisoned carpet" (because he chews the rug when angry), and observes that Mainwaring has wasted 438 hours on "useless blather". Naturally, Mainwaring is furious at Frazer's insubordinate behaviour. He consults the Home Guard manual and discovers a potential solution to the problem. Back on parade, he challenges Frazer to take